<%- HMR_DOWNLOAD_MANIFEST %> = <%- basicFunction("") %> {
  if (typeof fetch === "undefined") throw new Error("No browser support: need fetch API");
  return fetch(<%- PUBLIC_PATH %> + <%- GET_UPDATE_MANIFEST_FILENAME %>()).then(
  <%- basicFunction("response") %> {
      if (response.status === 404) return; // no update available
      if (!response.ok)
        throw new Error(
          "Failed to fetch update manifest " + response.statusText
        );
      return response.json();
    }
  );
};